Actually, pdfs are already postscript.
You could use a script which parses the postscript and selects the odd then the even pages.
Cups can be set to print to a program, you need to create a virtual printer.

The sig between the asterisks is so cool that only REALLY COOL people can even see it!

pdftk splits and reassembles PDF files, it has options to split out the odd or even or any other page range) into a separate file. Reading the man page, it would appear you can use it to generate two PDFs, for the even and odd pages, and even reverse the page order in one of them.

"Insanity: doing the same thing over and over again and expecting different results." (Albert Einstein)

Update: xpdf did barf over the diagrams pdf. It couldn't cope that the pages were rotated 90 deg to print on portrait paper like the main document, and printed them non-rotated but shrunk to fit instead.

Amazingly, the Document Viewer coped with this pdf.

"Klinger, do you know how many zoots were killed to make that one suit?" — BJ Hunnicutt, 4077 M*A*S*H